Normally a social network service (SNS) provided on a network has the ability to share information posted by users at a server. Sharing information with others may be performed through various acts such as writing something, uploading a photo or video, uploading a user's location, and the like.
In the social network service, it has been allowed to determine the range of information capable of being posted by a user and also to select receiving users, by ranking them as first-degree relationship, buddy, or the like, whom such information is opened to and shared with.
However, in this case, there has been a problem that it is disallowed to open the activity of a target of open or to request a target user to open his or her activity information.